The present invention relates to an applicator device for the application of a liquid or pasty product to a surface.
This applicator device is of the type comprising a receptacle which contains the liquid or pasty product to be applied and having its outlet opening provided with an applicator element which is porous and/or provided with holes. At the time of use, the product to be applied is made to pass into and/or through the applicator element, either by the user pressing on the receptacle if its walls are flexible, or simply by turning the receptacle over in such a manner that the applicator element is turned downwards and by shaking. The applicator element is then pressed with appropriate force on the surface to be treated so as to spread on said surface as well as possible the liquid or pasty product to be applied, the application rate depending on the pressing force.
Substances which can be so applied may belong to very different areas of use; mention can be made of cosmetic or pharmaceutical compositions, cleaning products, wax polishes, and similar items.
Moreover, depending on the size selected for it the applicator device can allow a number of applications or only be adapted for a single use, its reservoir then only containing the dose of substance necessary for a single dispensing.
In this type of applicator device, it is generally necessary to protect the product to be dispensed from the atmosphere during storage, before use in the case of an applicator device containing only a single dose, or before the first use in the case of an applicator which allows a number of successive uses of the substance. To this end there is fixed to the opening of the receptacle a cover formed by a film of tearable material which has been applied, in particular by heat-sealing, to the edge of the outlet opening of the receptacle; this cover separates during storage the product to be distributed from the applicator element. It is then necessary, at the time of use (or of first use) of the applicator device, to pierce the cover in order that the product to be dispensed can come to impregnate and/or pass through the applicator element.
In FR-A-2 595 587, it was proposed that the cover be pierced by an element bearing a trocar arranged in such a manner that pressing on the deformable applicator element before the first use, results in driving-in movement of the trocar to tear the cover. However this system is not entirely satisfactory because the elasticity of the fixing arm of the trocar may not be sufficient; furthermore the trocar can remain caught in the cover, which prevents the product from flowing freely.
According to the present invention, it has been found that these disadvantages are avoided by using a mobile and free rounded body which is arranged between the cover and the applicator element in order that, by pressing on the applicator element before use, this rounded body can be brought to tear the cover and then to fall into the receptacle. By correctly choosing the size, as well as the location of this rounded body, the rupturing of the cover can be brought about over a large diameter so as to allow arrival on the applicator element of the product to be dispensed under the best conditions. The rounded body does not catch on the cover but passes through it easily. Moreover, the use of a rounded body is economical because having to manufacture complicated pieces of small dimensions by moulding is avoided. In addition, the rounded body can, when it has fallen into the receptacle, serve as agitator/mixer, which is particularly advantageous in a case in which the product to be dispensed has high viscosity or is constituted by a dispersion or a thixotropic emulsion.
The present invention therefore provides a device for application of liquid or pasty products, comprising:- a receptacle; a deformable applicator element fixed to the outlet opening of the receptacle, the applicator element being separated from the receptacle during storage before use by a tearable cover, and means for perforating the cover, arranged between the applicator element and the cover and able to be operated by pressure on the deformable applicator element; characterized in that the means for perforating the cover is constituted by a mobile rounded body which is retained in position during storage before perforation of the cover by a retaining element and which perforates and passes through the cover to fall into the receptacle when pressure is applied to the deformable applicator element.
The rounded body is preferably a ball. In fact, after perforation, the edge of the tear of the cover only exerts a minimal frictional force of retention on a spherical ball. Moreover, whatever the shape of the receptacle, a ball will not tend to catch upon passing through the cover and will therefore always fall to the bottom. The rounded body could also take the form of an ellipsoid, in which case the bearing surface of the rounded body on the cover is greater and the tearing of the cover can in certain cases be more difficult.
The rounded body can be made of any material which is capable of not being crushed at the time when pressure is applied to the rounded body in order to perforate the cover and which has no undesirable effect on the product to be contained in the receptacle for dispensing. Use can advantageously be made of rounded bodies made of glass, of stainless steel, or of thermoplastic material.
In a particular embodiment, use can also be made of a rounded body made of a soluble or decomposable substance which constitutes a constituent of the product to be applied.
The applicator element can be constituted by any deformable material which is capable of allowing passage of the product to be dispensed. It can advantageously be constituted by a pad of synthetic resin foam, which may or may not be flocked on its external surface. It can also be constituted by a deformable wall which is made of elastomer and provided with holes, in particular with slots, for the passage of the product; in this latter case the applicator element can also be provided on its external surface with massaging roughnesses or points. The deformable wall made of elastomer is, in certain cases, advantageously lined on its internal surface with a layer of foam which may or may not be fixed to the elastomer wall.
In another embodiment of the device, the applicator element may be constituted by a metal or plastic grille lined on its internal surface by a layer of synthetic resin foam.
The retaining element has the function of retaining the rounded body opposite the point where the cover is to be perforated and of preventing said rounded body from moving during storage, so as to avoid accidental perforation of the cover. In addition it must have such a structure that it can be deformed and allow the transmission to the rounded body of the pressure exerted on the applicator element by the user and, possibly also the release of the rounded body in order that it may come into contact with the cover.
A piece in the form of a truncated cone or of a simple washer, whose central hole has a diameter greater than the greatest dimension of the cross-section of the rounded body, can be placed in the outlet opening of the receptacle and under the cover so that it prevents the cover from bulging when a pressure is exerted on the rounded body, and ensures better piercing of the cover. This piece can also facilitate the flowing of the product to be dispensed.
The retaining element ensures the position of the rounded body opposite the vicinity of the center of the cover because it is generally in this region that the cover is most easily tearable.
In a first embodiment the retaining element is constituted by a ring made of elastic material, in particular rubber, polyurethane, polyethylene, or vinyl polymer foam. This retaining ring is arranged between the cover and the applicator element itself. However, in cases in which the applicator element is constituted by a layer of foam or comprises a layer of foam, the applicator element and the retaining ring can constitute a single piece.
In a second embodiment of the invention, the retaining element is constituted by a star-shaped piece consisting of radial tabs connected to a support ring resting on that part of the cover which is fixed to the edge of the receptacle. The support ring is advantageously provided with teeth which are parallel to the longitudinal axis of the receptacle. These teeth make it possible to retain in position any layer of foam which constitutes the applicator element or lines it.
The applicator element is fixed to the outlet opening of the receptacle with the aid of a crimp edge which is integral with the receptacle. This crimp edge can be continuous or discontinuous, for example constituted by tongues. If the crimping is discontinuous, it is possible to arrange, in the space between two crimp tongues, auxiliary elements for combing, or for massage, or for scratching, which are in particular integral with the retaining element when this latter is constituted by a starshaped piece. It is to be noted that, according to an alternative, these auxiliary elements can be fixed to the lateral wall of the receptacle.
The receptacle of the applicator device according to the invention can take any form. It can be obtained by injection moulding, blow-moulding, extrusion, or other moulding technique.
The receptacle can be filled through its outlet opening, and then the dispensing head comprising the cover and retaining element for the rounded body, the rounded body itself and the applicator element, may be later applied to said opening. A receptacle which already comprises its dispensing head can also be filled through the bottom and the bottom can then be closed, for example, by welding.
When the user wishes to apply the product contained in the applicator device, he applies pressure to the deformable applicator element, driving down the ball until it tears the cover and falls into the receptacle.
In order that the invention may be better understood, three embodiments thereof, which are represented in the attached drawings, will be described below by way of purely illustrative and non-limitative examples.